I had a 3" in/dual 2.5" out 80 series flowmaster with no cat and the car sounded like a NASCAR! I just replaced that muffler with a 3" in/dual 3" out version (still no cat) the car is quiet! I don't get it!! It is more hollow, which i can understand, but the overall sound? Can someone explain this please!!!

 

The larger pipe flows air at a slower velocity, so it does not have as much energy which means less noise. The larger pipe also has more fluid dampening than the smaller pipe. The larger pipe also has lower frequency which results in a deeper sound which doesn't "sound" as loud as a higher frequency noise.

 

That makes sense, i still can't get over the difference though... WOW!

 

he's right! my Borla sytem sounds better with the 2nd restrictor plate in than it does with the wide open plate. although without a cat,the most open was the loudest.....hmmm

 

my flowmaster system took a couple weeks to get louder.

------------------
-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

To be installed eventually far far far into the future: Yours if the price is right and I don't have to ship :
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz

 

This is a slightly used muffler with new tailpipes.. i would have thought that it was already "broken in" hmm, oh well.